A typical complementary metal oxide semiconductor (CMOS) switch uses a p-type metal oxide semiconductor (PMOS) transistor and an n-type metal oxide semiconductor (NMOS) transistor to sample voltages that are received at an input. As an example, a PMOS transistor and an NMOS transistor are connected in parallel and share a common input and a common output. The gates of the PMOS transistor and the NMOS transistor are controlled by complementary signals for enabling the transistors, and when enabled, the switch allows the input to pass to the output. Thus, the output is the voltage sample on the input during the time in which the enable signals allow the transistors to be closed.
In addition, several switches may be connected in parallel, essentially comprising a multiplexer. For example, such a multiplexer may be used to sample voltages from several different points throughout a circuit. As an example, this arrangement may be used for an analog bus to monitor voltages around an integrated circuit chip and to send the sampled voltages to a voltage monitor. This arrangement works well for normal operation. Yet in many cases, the purpose of monitoring voltages through a circuit is to detect abnormal or undesirable voltage events. However, conventional devices may not be able to perform measurement functions for voltages outside of an expected range.